-/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */
-/* See LICENSE.txt file for copyright and license details. */
-
-
-/* TODO: Write description explaining that this simulates all 1D NN CAs, and explain briefly what all those terms imply. */
-/* TODO: Explain things like the topology of the space. */
-/* TODO: Explain how the numbering for a CA expands to the actual rules. */
-/* TODO: Briefly explain the four different classes of behavior and their implications. */
-/* TODO: Include a link to Wikipedia. */
-/* TODO: I suppose a lot of this stuff goes in the README instead. */
-/* TODO: Explain the data structures in detail. */
-/* TODO: Explain all the options, like the various starting conditions. */
-
-
-/* TODO: Check manpage for all functions I use and ensure my includes are correct. I don't want to depend on picking up includes via screenhack.h. */
-/* TODO: Verify everything in this file is C89. Get rid of things like '//' comments, pack all my declarations upfront, no stdint, etc. */
-/* TODO: Tabs -> Spaces before each commit. */
+/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */
+/* See LICENSE.txt file for copyright and license details. */
#include "screenhack.h"
-// Command line options
-// directory to output XBM files of each run (and call an external command to convert to PNGs?)
-// -save-dir STRING
-// number of generations to simulate
-// -num-generations N
-// delay time (speed of simulation)
-// -delay-usec N
-// foreground and background color
-// ??? (strings of some sort, but I need to look up what X resources to interact with)
-// display info overlay with CA number and start conditions?
-// -overlay
-// which ruleset number to use? Or random? Or random from small set of hand-selected interesting examples?
-// Options (with precedence): -rule N
-// -rule-curated
-// -rule-random
-// which starting population to use? Or random? Or one bit in middle? Or one bit on edge? (For random: Can I allow specifying a density like 25%, 50%, 75%?)
-// Options (with precedence): -population STRING (string is a comma separated list of cell IDs to populate, starting from 0)
-// -population-curated
-// -population-random
-// size of pixel square (e.g. 1x1, 2x2, 3x3, etc)
-// -pixel-size N
+/* Keep this source code C89 compliant per XScreensaver's instructions. */
+
+/* -------------------------------------------------------------------------- */
+/* Data Structures */
+/* -------------------------------------------------------------------------- */
struct state {
- /* Various X resources */
+ /* Various X resources */
Display * dpy;
Window win;
GC gc;
- // TODO: Explain that this holds the whole evolution of the CA and the actual displayed visualization is simply a snapshot into this pixmap.
- Pixmap evolution_history;
- size_t num_generations;
-
- // TODO: Explain all of these.
- int delay_microsec; // per generation
+ /* These hold the pixel value of the foreground and background colors in */
+ /* the same format as an XColor struct's "pixel" member. */
unsigned long fg, bg;
- int xlim, ylim, ypos; // explain roughly how and where we use these. Note: I'm not thrilled xlim/ylim since they are actually the width of the display, not the limit of the index (off by one). Change those names.
- Bool display_info;
- // TODO: Add an option for 'pixel size', so the user can define 1x1 or 2x2 or 3x3 or ... pixels. But then I need to deal with leftover pixels.
+ /* This Pixmap will eventually hold the entire evolution of the CA. The */
+ /* displayed portion of the CA's evolution is merely a viewport into this */
+ /* Pixmap. */
+ Pixmap evolution_history;
+
+ /* Together, these three values define the display viewport into the */
+ /* 'evolution_history' Pixmap. The pair 'dpy_width' and 'dpy_height' are */
+ /* simply the width and height of the display window. They remain */
+ /* unchanged during normal operation. However, 'ypos' tracks the location */
+ /* of the viewport in the 'evolution_history'. It must always keep the */
+ /* newest generation onscreen and display as much history as possible. */
+ int dpy_width, dpy_height, ypos;
+
+ /* In the 'current_generation' array, the value True means a cell is */
+ /* alive. We only need to track the current generation since our rulesets */
+ /* never consider older generations. Anything older can be rendered to */
+ /* the 'evolution_history' Pixmap and subsequently ignored. */
Bool * current_generation;
- uint8_t ruleset;
+
+ /* For more information on the encoding used for rule_number and on the */
+ /* method used to apply it: https://en.wikipedia.org/wiki/Wolfram_code */
+ uint8_t rule_number;
+
+ /* At the end of the simulation, the user is given time to admire the */
+ /* output. Delay is available to user as CLI option '-admiration-delay'. */
+ Bool admiration_in_progress;
+ size_t admiration_delay; /* ...in seconds. */
+
+ /* The following values correspond directly to independent CLI options. */
+ Bool random_rule;
+ int requested_rule;
+ int seed_density;
+ int cell_size; /* If cell_size=N then draw NxN pixels per cell. */
+ int delay_microsec; /* ...between calls to WolframAutomata_draw(). */
+ int num_generations; /* Reset simulation after this many generations. */
+
+ /* Not strictly necessary, but makes some code easier to read. */
+ size_t number_of_cells;
};
-static void *
-WolframAutomata_init(Display * dpy, Window win)
-{
- struct state * state = calloc(1, sizeof(*state)); // TODO: Check calloc() call
- XGCValues gcv;
- XWindowAttributes xgwa;
+enum seed_population {
+ random_cell,
+ middle_cell,
+ edge_cell
+};
- state->dpy = dpy;
- state->win = win;
+struct curated_ruleset {
+ uint8_t rule;
+ enum seed_population seed;
+};
- XGetWindowAttributes(state->dpy, state->win, &xgwa);
- state->xlim = xgwa.width;
- state->ylim = xgwa.height;
- state->ypos = 0; // TODO: Explain why.
+/* The following array contains rule numbers and starting seeds which were */
+/* preselected as being visually interesting. */
+static const struct curated_ruleset curated_ruleset_list[] = {
+ { 18, middle_cell},
+ { 30, middle_cell},
+ { 45, middle_cell},
+ { 54, middle_cell},
+ { 57, middle_cell},
+ { 73, middle_cell},
+ {105, middle_cell},
+ {109, middle_cell},
+ {129, middle_cell},
+ {133, middle_cell},
+ {135, middle_cell},
+ {150, middle_cell},
+ { 30, edge_cell},
+ { 45, edge_cell},
+ { 57, edge_cell},
+ { 60, edge_cell},
+ { 75, edge_cell},
+ {107, edge_cell},
+ {110, edge_cell},
+ {133, edge_cell},
+ {137, edge_cell},
+ {169, edge_cell},
+ {225, edge_cell},
+ { 22, random_cell},
+ { 30, random_cell},
+ { 54, random_cell},
+ { 62, random_cell},
+ { 90, random_cell},
+ {105, random_cell},
+ {108, random_cell},
+ {110, random_cell},
+ {126, random_cell},
+ {146, random_cell},
+ {150, random_cell},
+ {182, random_cell},
+ {184, random_cell},
+ {225, random_cell},
+ {240, random_cell}
+};
- state->fg = gcv.foreground = get_pixel_resource(state->dpy, xgwa.colormap, "foreground", "Foreground");
- state->bg = gcv.background = get_pixel_resource(state->dpy, xgwa.colormap, "background", "Background");
- state->gc = XCreateGC(state->dpy, state->win, GCForeground, &gcv);
+struct color_pair {
+ /* The type 'unsigned short' comes from the XColor struct definition, */
+ /* reproduced below. */
+ /* */
+ /* typedef struct { */
+ /* unsigned long pixel; */
+ /* unsigned short red, green, blue; */
+ /* char flags; */
+ /* char pad; */
+ /* } XColor; */
+ /* */
+ /* The red, green, and blue values are always in the range 0 to 65535 */
+ /* inclusive, independent of the number of bits actually used in the */
+ /* display hardware. The server scales these values to the range used */
+ /* by the hardware. Black is represented by (0,0,0), and white is */
+ /* represented by (65535,65535,65535). */
+ unsigned short fg_red, fg_green, fg_blue;
+ unsigned short bg_red, bg_green, bg_blue;
+};
- state->delay_microsec = get_integer_resource(state->dpy, "delay", "Integer");
- if (state->delay_microsec < 0) state->delay_microsec = 0;
+/* Since randomly selected colors would occasionally produce visually */
+/* indistinguishable foreground/background pairs, this array provides a */
+/* preselected list of complementary color pairs. */
+static const struct color_pair color_list[] = {
+ /* For mapping X11 color names to RGB values: */
+ /* https://www.ehdp.com/methods/x11-color-names-rgb-values.htm */
+ /* Remember that our values range from 0-65535 inclusive, so scale the */
+ /* usual 0-255 range accordingly. */
+ /* */
+ /* +---------------------------------------+ */
+ /* | foreground | | background | */
+ /* | red,green,blue | | red,green,blue | */
+ {65535, 0, 0, 0, 0, 0}, /* {"red", "black"}, */
+ {32767,32767, 0, 0, 0, 0}, /* {"olive", "black"}, */
+ { 0,32767,32767, 0, 0, 0}, /* {"teal", "black"}, */
+ {27524,22937,52428, 0, 0, 0}, /* {"slateblue", "black"}, */
+ {60947,33422,60947, 0, 0, 0}, /* {"violet", "black"}, */
+ {41287, 8519,61602, 0, 0, 0}, /* {"purple", "black"}, */
+ {65535,65535,65535, 0, 0, 0}, /* {"white", "black"}, */
+ {65535,65535,65535, 0,25558, 0}, /* {"white", "darkgreen"}, */
+ {65535,65535,65535, 36044, 0,36044}, /* {"white", "darkmagenta"}, */
+ {65535,65535,65535, 36044, 0, 0}, /* {"white", "darkred"}, */
+ {65535,65535,65535, 0, 0,36044}, /* {"white", "darkblue"}, */
+ {11796,20315,20315, 36494,65535,65535}, /* {"darkslategray", "darkslategray1"}, */
+ {45219,50461,57015, 11796,20315,20315}, /* {"lightsteelblue", "darkslategray"}, */
+ {10023,16448,35723, 16383,26869,57670}, /* {"royalblue4", "royalblue"}, */
+ {61166,57311,52428, 35723,33667,30840}, /* {"antiquewhite2", "antiquewhite4"}, */
+ {51914,65535,28784, 21626,27524,11796}, /* {"darkolivegreen1", "darkolivegreen"}, */
+ {49601,65535,49601, 26985,35723,26985}, /* {"darkseagreen1", "darkseagreen4"}, */
+ {65535,49151,52428, 36044, 0, 0}, /* {"pink", "darkred"}, */
+ {44563,55704,58981, 0,25558, 0}, /* {"lightblue", "darkgreen"}, */
+ {65535, 0, 0, 0, 0,65535}, /* {"red", "blue"}, */
+ {65535, 0, 0, 0,25558, 0}, /* {"red", "darkgreen"}, */
+ { 0,65535,65535, 0,32767,32767}, /* {"aqua", "teal"}, */
+ { 0, 0,36044, 0,32767,32767}, /* {"darkblue", "teal"}, */
+ {61602,58981,32767, 11796,36044,22281}, /* {"khaki", "seagreen"}, */
+ {61602,58981,32767, 21626,27524,11796}, /* {"khaki", "darkolivegreen"}, */
+ {30801,34733,39321, 11796,20315,20315}, /* {"lightslategray", "darkslategray"}, */
+ {65535,25558,18349, 11796,20315,20315}, /* {"tomato", "darkslategray"}, */
+ {65535,25558,18349, 0,36044,36044} /* {"tomato", "darkcyan"} */
+};
- // TODO: These should be command-line options, but I need to learn how the get_integer_resource() and similar functions work first.
- state->display_info = True;
- state->ruleset = 30;
- state->num_generations = 10000; // TODO: Enforce that this is >1 in order to hold the seed generation and at least one pass through WolframAutomata_draw(), which is where we check for a full pixmap.
-
- state->current_generation = calloc(1, (sizeof(*(state->current_generation))*(state->xlim))); // TODO: Check calloc() call TODO: Can't recall precedence; can I eliminate any parenthesis?
- // TODO: Make the starting state a user-configurable option. At least give the user some options like 'random', 'one-middle', 'one edge', etc.
- // Ideally accept something like a list of integers representing starting pixels to be "on".
- state->current_generation[state->xlim-1] = True;
-
- state->evolution_history = XCreatePixmap(state->dpy, state->win, state->xlim, state->num_generations, xgwa.depth);
- // Pixmap contents are undefined after creation. Explicitly set a black
- // background by drawing a black rectangle over the entire pixmap.
- XSetForeground(state->dpy, state->gc, state->bg);
- XFillRectangle(state->dpy, state->evolution_history, state->gc, 0, 0, state->xlim, state->num_generations);
- XSetForeground(state->dpy, state->gc, state->fg);
- // TODO: Need to draw starting generation on pixmap and increment state->ypos.
+/* -------------------------------------------------------------------------- */
+/* Helper Functions */
+/* -------------------------------------------------------------------------- */
- return state;
+/* Some rules demonstrate behavior dominated by the starting seed. Thus, in */
+/* addition to a 50/50 random split of active/inactive cells, include other, */
+/* more biased random distributions in order to demonstrate such behavior. */
+static void
+randomize_seed_density(struct state * state)
+{
+ switch (random() % 3) {
+ case 0: state->seed_density = 30; break;
+ case 1: state->seed_density = 50; break;
+ case 2: state->seed_density = 70; break;
+ }
+}
+
+static void
+generate_random_seed(struct state * state)
+{
+ int i;
+ for (i = 0; i < state->number_of_cells; i++) {
+ state->current_generation[i] = ((random() % 100) < state->seed_density) ? True : False;
+ }
}
-// TODO: function decorations?
-// TODO: Explain why this santizes the index for accessing current_generation (i.e. it creates a circular topology).
-size_t
+/* This function sanitizes the index used to access cells in a generation. */
+/* Specifically, it wraps the index, creating a circular universe for the */
+/* cells and ensuring every cell has two neighbors. */
+static size_t
sindex(struct state * state, int index)
{
while (index < 0) {
- index += state->xlim;
+ index += state->number_of_cells;
}
- while (index >= state->xlim) {
- index -= state->xlim;
+ while (index >= state->number_of_cells) {
+ index -= state->number_of_cells;
}
return (size_t) index;
}
-// TODO: function decorations?
-// TODO: At least give a one-sentence explanation of the algorithm since this function is the core of the simulation.
-Bool
+/* For more information on the encoding used for state->rule_number and on */
+/* the method used to apply it: https://en.wikipedia.org/wiki/Wolfram_code */
+static Bool
calculate_cell(struct state * state, int cell_id)
{
uint8_t cell_pattern = 0;
cell_pattern |= 1;
}
}
- if ((state->ruleset >> cell_pattern) & 1) {
+ if ((state->rule_number >> cell_pattern) & 1) {
return True;
} else {
return False;
}
}
-// TODO: function decorations?
-void
+static void
render_current_generation(struct state * state)
{
size_t xpos;
- for (xpos = 0; xpos < state->xlim; xpos++) {
+ for (xpos = 0; xpos < state->number_of_cells; xpos++) {
if (state->current_generation[xpos] == True) {
- XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos, state->ypos, 1, 1);
+ XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos*state->cell_size, state->ypos, state->cell_size, state->cell_size);
+ } else {
+ XSetForeground(state->dpy, state->gc, state->bg);
+ XFillRectangle(state->dpy, state->evolution_history, state->gc, xpos*state->cell_size, state->ypos, state->cell_size, state->cell_size);
+ XSetForeground(state->dpy, state->gc, state->fg);
}
}
}
+/* -------------------------------------------------------------------------- */
+/* Screenhack API Functions */
+/* -------------------------------------------------------------------------- */
+
+static Bool
+WolframAutomata_event(Display * dpy, Window win, void * closure, XEvent * event)
+{
+ return False;
+}
+
+static void
+WolframAutomata_free(Display * dpy, Window win, void * closure)
+{
+ struct state * state = closure;
+ XFreeGC(state->dpy, state->gc);
+ XFreePixmap(state->dpy, state->evolution_history);
+ free(state->current_generation);
+ free(state);
+}
+
+static void *
+WolframAutomata_init(Display * dpy, Window win)
+{
+ struct state * state;
+ XGCValues gcv;
+ XWindowAttributes xgwa;
+ XColor fg, bg;
+ XColor blackx, blacks;
+ size_t color_index;
+ const struct curated_ruleset * curated_ruleset = NULL;
+
+ state = calloc(1, sizeof(*state));
+ if (!state) {
+ fprintf(stderr, "ERROR: Failed to calloc() for state struct in WolframAutomata_init().\n");
+ exit(EXIT_FAILURE);
+ }
+
+ state->dpy = dpy;
+ state->win = win;
+
+ XGetWindowAttributes(state->dpy, state->win, &xgwa);
+ state->dpy_width = xgwa.width;
+ state->dpy_height = xgwa.height;
+ state->ypos = 0;
+
+ state->admiration_delay = get_integer_resource(state->dpy, "admiration-delay", "Integer");
+ state->admiration_in_progress = False;
+
+ /* Set foreground and background colors for active/inactive cells. Either */
+ /* the user provided an index into the pre-defined color_list[] or a */
+ /* random entry from that same array should be selected. */
+ color_index = get_integer_resource(state->dpy, "color-index", "Integer");
+ if (color_index == -1) {
+ color_index = random() % sizeof(color_list)/sizeof(color_list[0]);
+ } else if (color_index >= sizeof(color_list)/sizeof(color_list[0])) {
+ fprintf(stderr, "WARNING: Color index out of range.\n");
+ color_index = 0;
+ }
+ fg.red = color_list[color_index].fg_red;
+ fg.green = color_list[color_index].fg_green;
+ fg.blue = color_list[color_index].fg_blue;
+ bg.red = color_list[color_index].bg_red;
+ bg.green = color_list[color_index].bg_green;
+ bg.blue = color_list[color_index].bg_blue;
+ XAllocColor(state->dpy, xgwa.colormap, &fg);
+ XAllocColor(state->dpy, xgwa.colormap, &bg);
+ state->fg = gcv.foreground = fg.pixel;
+ state->bg = gcv.background = bg.pixel;
+
+ state->gc = XCreateGC(state->dpy, state->win, GCForeground, &gcv);
+
+ /* Set the size of each simulated cell to NxN pixels for cell_size=N. */
+ if (get_boolean_resource(state->dpy, "random-cell-size", "Boolean")) {
+ /* Although we are choosing the pixel size 'randomly', a truly random */
+ /* selection would bias toward large numbers since there are more of */
+ /* them. To avoid this, we select a random number for a bit shift, */
+ /* resulting in a pixel size of 1, 2, 4, 8, 16 or 32, equally likely. */
+ state->cell_size = 1 << (random() % 6);
+ } else {
+ state->cell_size = get_integer_resource(state->dpy, "cell-size", "Integer");
+ }
+ if (state->cell_size < 1) state->cell_size = 1;
+ if (state->cell_size > state->dpy_width) state->cell_size = state->dpy_width;
+
+ /* Larger cell sizes won't always evenly divide the number of pixels in */
+ /* our window. In order to avoid a black stripe down the edge, '+1' here */
+ /* to ensure we are slightly oversize rather than undersize. */
+ state->number_of_cells = (state->dpy_width / state->cell_size) + 1;
+
+ /* Set the delay (in microseconds) between simulation of each generation */
+ /* of the simulation, also known as the delay between calls to */
+ /* WolframAutomata_draw(), which simulates one generation per call. */
+ if (get_boolean_resource(state->dpy, "random-delay", "Boolean")) {
+ /* When randomly setting the delay, the problem is to avoid being too */
+ /* fast or too slow, as well as ensuring slower speeds are chosen */
+ /* with the same likelihood as faster speeds, as perceived by a */
+ /* human. By empirical observation, we note that for 1x1 up to 4x4 */
+ /* pixel cell sizes, values for state->delay_microsec between */
+ /* 2048 (2^11) and 16556 (2^14) produce pleasant scroll rates. To */
+ /* maintain this appearance, we bitshift state->cell_size down until */
+ /* it is a maximum of 4x4 pixels in size, record how many bitshifts */
+ /* took place, and then shift our valid window for */
+ /* state->delay_microsec up by an equal number of bitshifts. For */
+ /* example, if state->cell_size=9, then it takes one right shift to */
+ /* reach state->cell_size=4. Thus, the valid window for */
+ /* state->delay_microsec becomes 4096 (2^12) up to 32768 (2^15). */
+ size_t pixel_shift_range = 1;
+ size_t cell_size_temp = state->cell_size;
+ while (cell_size_temp > 4) {
+ cell_size_temp >>= 1;
+ pixel_shift_range++;
+ }
+ /* In the below line, '3' represents the total range, namely '14-11' */
+ /* from '2^14' and '2^11' as the endpoints. Similarly, the '11' in */
+ /* the below line represents the starting point of this range, from */
+ /* the exponent in '2^11'. */
+ state->delay_microsec = 1 << ((random() % 3) + 11 + pixel_shift_range);
+ } else {
+ state->delay_microsec = get_integer_resource(state->dpy, "delay", "Integer");
+ }
+ if (state->delay_microsec < 0) state->delay_microsec = 0;
+
+ /* Set the number of generations to simulate before wiping the simulation */
+ /* and re-running with new settings. */
+ if (get_boolean_resource(state->dpy, "random-length", "Boolean")) {
+ /* By empirical observation, keep the product */
+ /* state->num_generations * state->cell_size */
+ /* below 10,000 to avoid BadAlloc errors from the X server due to */
+ /* requesting an enormous pixmap. This value works on both a 12 core */
+ /* Xeon with 108 GiB of RAM and a Sun Ultra 2 with 2 GiB of RAM. */
+ state->num_generations = random() % (10000 / state->cell_size);
+ /* Ensure selected value is large enough to at least fill the screen. */
+ /* Cast to avoid overflow. */
+ if ((long)state->num_generations * (long)state->cell_size < state->dpy_height) {
+ state->num_generations = (state->dpy_height / state->cell_size) + 1;
+ }
+ } else {
+ state->num_generations = get_integer_resource(state->dpy, "length", "Integer");
+ }
+ /* The minimum number of generations is 2 since we must allocate enough */
+ /* space to hold the seed generation and at least one pass through */
+ /* WolframAutomata_draw(), which is where we check whether or not we've */
+ /* reached the end of the pixmap. */
+ if (state->num_generations < 0) state->num_generations = 2;
+ /* The maximum number of generations is cell_size dependent. This is a */
+ /* soft limit and may be increased if you have plenty of RAM (and a */
+ /* cooperative X server). The value 10,000 was determined empirically. */
+ if ((long)state->num_generations * (long)state->cell_size > 10000) {
+ state->num_generations = 10000 / state->cell_size;
+ }
+
+ /* Time to figure out which rule to use for this simulation. */
+ /* We ignore any weirdness resulting from the following casts since every */
+ /* bit pattern is also a valid rule; if the user provides weird input, */
+ /* then we'll return weird (but well-defined!) output. */
+ state->requested_rule = get_integer_resource(state->dpy, "rule", "Integer");
+ state->random_rule = get_boolean_resource(state->dpy, "random-rule", "Boolean");
+ /* Through the following set of branches, we enforce CLI flag precedence. */
+ if (state->random_rule) {
+ /* If this flag is set, the user wants truly random rules rather than */
+ /* random rules from a curated list. */
+ state->rule_number = (uint8_t) random();
+ } else if (state->requested_rule != -1) {
+ /* The user requested a specific rule. Use it. */
+ state->rule_number = (uint8_t) state->requested_rule;
+ } else {
+ /* No command-line options were specified, so select rules randomly */
+ /* from a curated list. */
+ size_t number_of_array_elements = sizeof(curated_ruleset_list)/sizeof(curated_ruleset_list[0]);
+ curated_ruleset = &curated_ruleset_list[random() % number_of_array_elements];
+ state->rule_number = curated_ruleset->rule;
+ }
+
+ /* Time to construct the seed generation for this simulation. */
+ state->current_generation = calloc(1, sizeof(*state->current_generation)*state->number_of_cells);
+ if (!state->current_generation) {
+ fprintf(stderr, "ERROR: Failed to calloc() for cell generation in WolframAutomata_init().\n");
+ exit(EXIT_FAILURE);
+ }
+ if (curated_ruleset) {
+ /* If we're using a curated ruleset, ignore any CLI flags related to */
+ /* setting the seed generation, instead drawing that information from */
+ /* the curated ruleset. */
+ switch (curated_ruleset->seed) {
+ case random_cell: randomize_seed_density(state); generate_random_seed(state); break;
+ case middle_cell: state->current_generation[state->number_of_cells/2] = True; break;
+ case edge_cell : state->current_generation[0] = True; break;
+ }
+ } else {
+ /* If we're not using a curated ruleset, process any relevant flags */
+ /* from the user, falling back to a random seed generation if nothing */
+ /* else is specified. */
+ if (get_boolean_resource(state->dpy, "seed-left", "Boolean")) {
+ state->current_generation[0] = True;
+ } else if (get_boolean_resource(state->dpy, "seed-center", "Boolean")) {
+ state->current_generation[state->number_of_cells/2] = True;
+ } else if (get_boolean_resource(state->dpy, "seed-right", "Boolean")) {
+ state->current_generation[state->number_of_cells-1] = True;
+ } else if (get_integer_resource(state->dpy, "seed-density", "Integer") != -1) {
+ state->seed_density = get_integer_resource(state->dpy, "seed-density", "Integer");
+ if (state->seed_density < 0 || state->seed_density > 100) state->seed_density = 50;
+ generate_random_seed(state);
+ } else {
+ randomize_seed_density(state);
+ generate_random_seed(state);
+ }
+ }
+
+ state->evolution_history = XCreatePixmap(state->dpy, state->win, state->dpy_width, state->num_generations*state->cell_size, xgwa.depth);
+ /* Pixmap contents are undefined after creation. Explicitly set a black */
+ /* background by drawing a black rectangle over the entire pixmap. */
+ XAllocNamedColor(state->dpy, DefaultColormapOfScreen(DefaultScreenOfDisplay(state->dpy)), "black", &blacks, &blackx);
+ XSetForeground(state->dpy, state->gc, blacks.pixel);
+ XFillRectangle(state->dpy, state->evolution_history, state->gc, 0, 0, state->dpy_width, state->num_generations*state->cell_size);
+ XSetForeground(state->dpy, state->gc, state->fg);
+ render_current_generation(state);
+ state->ypos += state->cell_size;
+
+ return state;
+}
+
static unsigned long
WolframAutomata_draw(Display * dpy, Window win, void * closure)
{
-// TODO: Mark these basic sections of the function
-//draw()
-// calculate (and store) new generation
-// draw new generation as line of pixels on pixmap
-// calculate current 'viewport' into pixmap
-// display on screen
-// check for termination condition
-
struct state * state = closure;
int xpos;
int window_y_offset;
- Bool new_generation[state->xlim];
- for (xpos = 0; xpos < state->xlim; xpos++) {
+ /* Calculate and record new generation. */
+ Bool * new_generation = malloc(state->dpy_width * sizeof(Bool));
+ if (new_generation == NULL) {
+ fprintf(stderr, "ERROR: Failed to malloc() when calculating new generation.\n");
+ exit(EXIT_FAILURE);
+ }
+ for (xpos = 0; xpos < state->number_of_cells; xpos++) {
new_generation[xpos] = calculate_cell(state, xpos);
}
- for (xpos = 0; xpos < state->xlim; xpos++) {
+ for (xpos = 0; xpos < state->number_of_cells; xpos++) {
state->current_generation[xpos] = new_generation[xpos];
}
+ free(new_generation);
render_current_generation(state);
- // Was this the final generation of this particular simulation? If so, give
- // the user a moment to bask in the glory of our output and then start a
- // new simulation.
- if (state->ypos < state->num_generations-1) {
- state->ypos++;
+ /* Check for end of simulation. */
+ if (state->ypos/state->cell_size < state->num_generations-1) {
+ /* Life continues. */
+ state->ypos += state->cell_size;
} else {
- // TODO: Wait for a second or two, clear the screen and do a new iteration with suitably changed settings.
- // Note: Since we can't actually loop or sleep here, we need to add a flag to the state struct to indicate that we're in an 'admiration timewindow' (and indicate when it should end)
- while (1) continue;
+ /* We have reached the end of this simulation. Give the user a moment */
+ /* to bask in the glory of our output, then reset. */
+ if (state->admiration_in_progress) {
+ WolframAutomata_free(dpy, win, state);
+ closure = WolframAutomata_init(dpy, win);
+ } else {
+ state->admiration_in_progress = True;
+ return 1000000 * state->admiration_delay;
+ }
}
- // Calculate the vertical offset of the current 'window' into the history
- // of the CA. After the CA's evolution extends past what we can display, have
- // the window track the current generation and most recent history.
- if (state->ypos < state->ylim) {
+ /* Calculate vertical offset of current 'window' into the CA's history. */
+ /* After the CA evolution exceeds our display extents, make window track */
+ /* current generation, scrolling display to follow newest generation. */
+ if (state->ypos < state->dpy_height) {
window_y_offset = 0;
} else {
- window_y_offset = state->ypos - (state->ylim - 1);
+ window_y_offset = state->ypos - (state->dpy_height - 1);
}
- // Render everything to the display.
- XCopyArea(state->dpy, state->evolution_history, state->win, state->gc, 0, window_y_offset, state->xlim, state->ylim, 0, 0);
- // TODO: Print info on screen if display_info is true. Will need fonts/etc. Do I want to create a separate pixmap for this during the init() function and then just copy the pixmap each time we draw the screen in draw()?
+ /* Render a window into the CA history. */
+ XCopyArea(state->dpy, state->evolution_history, state->win, state->gc, 0, window_y_offset, state->dpy_width, state->dpy_height, 0, 0);
return state->delay_microsec;
}
+static void
+WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
+{
+ struct state * state = closure;
+ XWindowAttributes xgwa;
+ XGetWindowAttributes(state->dpy, state->win, &xgwa);
+
+ /* Only restart the simulation if the window changed size. */
+ if (state->dpy_width != xgwa.width || state->dpy_height != xgwa.height) {
+ WolframAutomata_free(dpy, win, closure);
+ closure = WolframAutomata_init(dpy, win);
+ }
+}
+
static const char * WolframAutomata_defaults[] = {
- ".background: black",
- ".foreground: white",
- "*delay: 2500",
+ "*admiration-delay: 5",
+
+ "*color-index: -1",
+
+ "*cell-size: 2",
+ "*random-cell-size: False",
+
+ "*delay: 25000",
+ "*random-delay: False",
+
+ "*length: 5000",
+ "*random-length: False",
+
+ "*rule: -1",
+ "*random-rule: False",
+
+ "*seed-density: -1",
+ "*seed-left: False",
+ "*seed-center: False",
+ "*seed-right: False",
+
0
};
static XrmOptionDescRec WolframAutomata_options[] = {
- { "-delay", ".delay", XrmoptionSepArg, 0 },
- { 0, 0, 0, 0 }
-};
+ { "-admiration-delay", ".admiration-delay", XrmoptionSepArg, 0 },
-static Bool
-WolframAutomata_event(Display * dpy, Window win, void * closure, XEvent * event)
-{
- return False;
-}
+ { "-color-index", ".color-index", XrmoptionSepArg, 0 },
-static void
-WolframAutomata_free(Display * dpy, Window win, void * closure)
-{
- struct state * state = closure;
- XFreeGC(state->dpy, state->gc);
- XFreePixmap(state->dpy, state->evolution_history);
- free(state->current_generation);
- free(state);
-}
+ { "-cell-size", ".cell-size", XrmoptionSepArg, 0 },
+ { "-random-cell-size", ".random-cell-size", XrmoptionNoArg, "True" },
-static void
-WolframAutomata_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
-{
- WolframAutomata_free(dpy, win, closure);
- WolframAutomata_init(dpy, win);
-}
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-random-delay", ".random-delay", XrmoptionNoArg, "True" },
+
+ { "-length", ".length", XrmoptionSepArg, 0 },
+ { "-random-length", ".random-length", XrmoptionNoArg, "True" },
+
+ { "-rule", ".rule", XrmoptionSepArg, 0 },
+ { "-random-rule", ".random-rule", XrmoptionNoArg, "True" },
+
+ { "-seed-density", ".seed-density", XrmoptionSepArg, 0 },
+ { "-seed-left", ".seed-left", XrmoptionNoArg, "True" },
+ { "-seed-center", ".seed-center", XrmoptionNoArg, "True" },
+ { "-seed-right", ".seed-right", XrmoptionNoArg, "True" },
+
+ { 0, 0, 0, 0 }
+};
XSCREENSAVER_MODULE ("1D Nearest-Neighbor Cellular Automata", WolframAutomata)